In the past, and up to today, most quality bedding blankets are woven. The conventional manner of forming fabrics for use as bedding blankets involves the weaving of yarns on a flat bed loom, and the subsequent finishing of the woven fabric to increase or enhance its bulk and stability, followed by various brushing or napping operations to raise the pile and loft of the fibers. As the selvedge is unfinished it must be hemmed. Further, shedding and pilling is experienced due to the broken fibers resulting from the napping and brushing operations employed in the formation of the pile and loft. While this problem can be minimized through the use of a greater density of heavier yarns the resultant fabric has been relatively expensive to create.
Two alternative fabrics and methods of creating them have more recently been employed. One teaches the manufacture of blankets employing non-woven fabrics and the other the manufacture of blankets employing flocked fabrics.
Non-woven fabrics are formed by needle looming fiber batts to produce an integrated fabric which are then subjected to napping and brushing operations. These non-woven fabrics have permitted the manufacture of a less expensive high loft blanket, but often do not achieve the drape and hand of woven blankets, and, the blankets are often subject to localized weaknesses which result in the formation of holes after prolonged use. Additionally, difficulty is experienced in controlling shedding and pilling, the control of this problem usually requiring chemical bonding of the napped and raised fibers, and the further loss of drape and hand of the fabric.
Where flocked fabrics have been utilized as a blanket fabric, generally short staple fibers are attached to a fabric surface with an adhesive facing either by spray deposition or by an electrostatic method. Velvet-like surfaces may be formed by employing flock fiber with lengths of approximately 1 mm, and plush-like surfaces may be formed by employing flock fibers with lengths of approximately 1.5 mm or more.
Flocked blanket fabric, while providing the tactile quality of a velvet or plush, has many deficiencies. For example, the overall hand of the fabric is sponge-like, and sections of the fabric under hand pressure ofen exhibit a rubber-like resistance and lacks the drape and hand of conventionally woven blanket fabrics. Further, delamination and wearing away of the flock often results in bald spots, a result often encountered in dry cleaning or laundering. Carefully controlled conditions of care are thus often required to prevent damage to the blanket.
Heretofore the creation of quality blanket materials by knitting has not been considered practical. By and large such knitted materials have had extremely poor stability, especially in the transverse or warp direction. Further, blanket materials have raised faces on both surfaces or faces of the blanket. This requires that both faces be napped and raised to create dual fleece-like facings. However, known knit fabrics do not retain dimensional stability and integrity when subjected to napping on both faces.
While knitted fabrics having a single fleece-facing are well known in the art, these single faced fabrics generally do not have the dimensional stability required of blanket material. Such fabrics may be made in a number of known ways, including knitting facing yarns into a knitted substrate and overfeeding of the facing yarn to create enlarged loops which can be napped and brushed to create a fleece surface.
An example of this technique is disclosed in U.S. Pat. No. 3,090,097, to Ruckstuhl, issued May 21, 1963. Ruckstuhl teaches a conventional nap construction produced on a double bar warp knit loom, the direction of travel of the respective bars being uni-directional, and resulting in a knitted fabric which subsequently can be processed into a single faced velvet-like knitted fabric.
It has been suggested that the loops may be presented on both surfaces of the substrate, such as shown in U.S. Pat. No. 3,434,306 to Auville et al. issued Mar. 25, 1969. Auville et al. teaches the manufacture of warp knit terry fabrics employing a double bar knitting machine in which the yarns of one of the bars is overfed to provide a double-sided terry fabric. However, in providing loops on both faces, the knit structure becomes dimensionally unstable, and would therefore be unsatisfactory as a blanket material.
In U.S. Pat. No. 3,255,615, to Schwartz, issued June 14, 1966, a double-sided terry loop warp knit fabric is created using a modified Atlas stitch. In order to provide loops on both faces, Schwartz teaches the knitting of one-half of his loops on one side of the fabric and a loop lay-in on the lap side of the fabric. The substrate is therefore vulnerable to severe weakening if the resultant fabric is subjected to napping to raise the pile and loft of the facing yarn. As a result it is unsuitable as a blanket material. Further, even if napping were possible, the fabric is unstable dimensionally in both the longitudinal and the lateral directions.
Where a third bar has been employed in the knitting, known three bar constructions do not provide the stability and necessary surface characteristics for blankets. For example, U.S. Pat. No. 3,517,530, to Magnus, issued June 30, 1970, teaches the formation of a terry loop fabric knit on a three bar warp knit machine. In addition to being dimensionally unstable, the fabric does not produce a nappable surface on the lap side.
Similarly, in U.S. Pat. No. 4,193,137, to Heck, issued Mar. 18, 1980, where a warp knitted fabric having pile loops on both of its faces is provided, the fabric is unsuitable for napping operations, in that napping will significantly weaken the structural integrity of the fabric, even further reducing its dimensional stability.